What a test plan should contain?

A software project test plan is a document that describes the objectives, scope, approach, and focus of a software testing effort. The process of preparing a test plan is a useful way to think through the efforts needed to validate the acceptability of a software product. The completed document will help people outside the test group understand the 'why' and 'how' of product validation. It should be thorough enough to be useful but not so thorough that no one outside the test group will read it. A test plan states what the items to be tested are, at what level they will be tested, what sequence they are to be tested in, how the test strategy will be applied to the testing of each item, and describes the test environment. A test plan should ideally be organisation wide, being applicable to all of an organisations software developments. The objective of each test plan is to provide a plan for verification, by testing the software, the software produced fulfils the functional or design statements of the appropriate software specification. In the case of acceptance testing and system testing, this generally means the Functional Specification. The first consideration when preparing the Test Plan is who the intended audience is – i.e. the audience for a Unit Test Plan would be different, and thus the content would have to be adjusted accordingly. You should begin the test plan as soon as possible. Generally it is desirable to begin the master test plan as the same time the Requirements documents and the Project Plan are being developed. Test planning can (and should) have an impact on the Project Plan. Even though plans that are written early will have to be changed during the course of the development and testing, but that is important, because it records the progress of the testing and helps planners become more proficient.